Skip to content

Latest commit

 

History

History
95 lines (78 loc) · 4.29 KB

information-schema-processlist.md

File metadata and controls

95 lines (78 loc) · 4.29 KB
Raw
title summary aliases
PROCESSLIST
了解 information_schema 表 `PROCESSLIST`。
/docs-cn/dev/information-schema/information-schema-processlist/

PROCESSLIST

PROCESSLIST 和 SHOW PROCESSLIST 的功能一样，都是查看当前正在处理的请求。

PROCESSLIST 表比 SHOW PROCESSLIST 的结果多出下面几列：

  • MEM 列：MEM 显示正在处理的请求已使用的内存，单位是 byte。
  • TxnStart列：显示事务的开始时间

{{< copyable "sql" >}}

USE information_schema;
DESC processlist;
+----------+---------------------+------+------+---------+-------+
| Field    | Type                | Null | Key  | Default | Extra |
+----------+---------------------+------+------+---------+-------+
| ID       | bigint(21) unsigned | NO   |      | 0       |       |
| USER     | varchar(16)         | NO   |      |         |       |
| HOST     | varchar(64)         | NO   |      |         |       |
| DB       | varchar(64)         | YES  |      | NULL    |       |
| COMMAND  | varchar(16)         | NO   |      |         |       |
| TIME     | int(7)              | NO   |      | 0       |       |
| STATE    | varchar(7)          | YES  |      | NULL    |       |
| INFO     | binary(512)         | YES  |      | NULL    |       |
| MEM      | bigint(21) unsigned | YES  |      | NULL    |       |
| TxnStart | varchar(64)         | NO   |      |         |       |
+----------+---------------------+------+------+---------+-------+
10 rows in set (0.00 sec)

{{< copyable "sql" >}}

SELECT * FROM processlist\G
*************************** 1. row ***************************
      ID: 16
    USER: root
    HOST: 127.0.0.1
      DB: information_schema
 COMMAND: Query
    TIME: 0
   STATE: autocommit
    INFO: SELECT * FROM processlist
     MEM: 0
TxnStart: 
1 row in set (0.00 sec)

PROCESSLIST 表各列的含义如下：

  • ID：客户连接 ID。
  • USER：执行当前 PROCESS 的用户名。
  • HOST：客户连接的地址。
  • DB：当前连接的默认数据库名。
  • COMMAND：当前 PROCESS 执行的命令类型。
  • TIME：当前 PROCESS 的已经执行的时间，单位是秒。
  • STATE：当前连接的状态。
  • INFO：正在处理的请求语句。
  • MEM：正在处理的请求已使用的内存，单位是 byte。
  • TxnStart列：显示事务的开始时间

CLUSTER_PROCESSLIST

CLUSTER_PROCESSLIST 是 PROCESSLIST 对应的集群系统表，用于查询集群中所有 TiDB 节点的 PROCESSLIST 信息。CLUSTER_PROCESSLIST 表结构上比 PROCESSLIST 多一列 INSTANCE，表示该行数据来自的 TiDB 节点地址。

{{< copyable "sql" >}}

SELECT * FROM cluster_processlist;
+-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+
| INSTANCE        | ID  | USER | HOST     | DB   | COMMAND | TIME | STATE      | INFO                                                 | MEM | TxnStart                               |
+-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+
| 10.0.1.22:10080 | 150 | u1   | 10.0.1.1 | test | Query   | 0    | autocommit | select count(*) from usertable                       | 372 | 05-28 03:54:21.230(416976223923077223) |
| 10.0.1.22:10080 | 138 | root | 10.0.1.1 | test | Query   | 0    | autocommit | SELECT * FROM information_schema.cluster_processlist | 0   | 05-28 03:54:21.230(416976223923077220) |
| 10.0.1.22:10080 | 151 | u1   | 10.0.1.1 | test | Query   | 0    | autocommit | select count(*) from usertable                       | 372 | 05-28 03:54:21.230(416976223923077224) |
| 10.0.1.21:10080 | 15  | u2   | 10.0.1.1 | test | Query   | 0    | autocommit | select max(field0) from usertable                    | 496 | 05-28 03:54:21.230(416976223923077222) |
| 10.0.1.21:10080 | 14  | u2   | 10.0.1.1 | test | Query   | 0    | autocommit | select max(field0) from usertable                    | 496 | 05-28 03:54:21.230(416976223923077225) |
+-----------------+-----+------+----------+------+---------+------+------------+------------------------------------------------------+-----+----------------------------------------+